Gonadotropin-releasing hormone agonist protocols for pituitary suppression in assisted reproduction

When comparing long and short GnRHa protocols, we found little or no difference in live birth and ongoing pregnancy rates, but there was evidence that the long protocol may improve clinical pregnancy rates overall. We were uncertain of any difference in OHSS and miscarriage rates for all comparisons, which were reported by only two studies each. There was insufficient evidence to draw any conclusions regarding other adverse effects or the cost-effectiveness and acceptability of the different treatment protocols.